Taylor Swift has unexpectedly released a remix as the fourth single from her 2014 album 1989. The highly-anticipated video for Bad Blood (Remix) had its world premiere at the start of 2015 Billboard music awards, and shows Swift as her action hero alter ego Catastrophe.

Its long list of celebrity cameos – featuring many of Swift’s real-life “girl gang”, including model Cara Delevingne and Girls creator Lena Dunham – was detailed in the leadup to its release, but the fact that the single would be a remix had not previously been known.

Kendrick Lamar, appearing as “Welvin Da Great”, contributes two previously-unheard verses, and the track has more electronic elements than the album version on 1989.

Bad Blood – hinted by Swift to be about a falling out with fellow pop star Katy Perry – was singled out by many reviewers as the weakest point of an otherwise well-received album. The album’s previous singles were Shake It Off and Blank Space (both of which made number one in the US) and Style.